Simplify the following expression: $y = \dfrac{n^2 - 2n - 80}{n + 8} $
Explanation: First factor the polynomial in the numerator. $ n^2 - 2n - 80 = (n + 8)(n - 10) $ So we can rewrite the expression as: $y = \dfrac{(n + 8)(n - 10)}{n + 8} $ We can divide the numerator and denominator by $(n + 8)$ on condition that $n \neq -8$ Therefore $y = n - 10; n \neq -8$